How many people live in your home? That's an easy question, right? If it's just you, your mom and dad, and your two sisters, that would be five people total.

But what about your entire neighborhood? And how many people live in your town? What about your state? How about the whole country? Those aren't so easy to answer, are they? It would probably take quite a while to count all the people in your town, state, and country.

If you look for these population numbers online, you'll find that they do exist. So did someone actually go out and count all these people? Not exactly…but they were counted with the help of something called the census.

The United States Constitution requires that the population of the country be enumerated (counted) every 10 years. This is done by the U.S. Census Bureau through a process called the census.

The first census after the American Revolution occurred in 1790. Since that time, 22 decennial (every 10 years) censuses have been conducted. The last census happened in 2010, and the next census will take place in 2020.

Why does the government go to the trouble to count everyone every 10 years? It's actually important to know how many people live in the U.S. for a variety of reasons.

For example, our government requires that the House of Representatives in Congress reflect population accurately. Larger states receive more representatives than smaller states. The census results help the government correctly divide up the Congressional seats.

In addition, your tax money is used by the federal government for a variety of things, including schools, hospitals, and roads. Like seats in the House of Representatives, census data helps the government decide how to fairly divide up federal program money based on the number of people being served in an area.

The U.S. Census Bureau uses two methods to count everyone. Questionnaires are mailed to every home in the country and census workers travel door-to-door in certain areas throughout the county. The goal is to count every person living in the United States, regardless of nationality, citizenship status, race, age, or gender.

Unfortunately, not everyone is counted during a census. Some people refuse to give their information to be counted. This can be for a variety of reasons. Some people don't want to give their confidential information to the government. Other people, including undocumented immigrants, fear the government will try to make them leave the country if they share their personal information.

To make up for these factors, the U.S. Census Bureau uses statistics and other population information gathered by the states to estimate the number of people who may not have been counted. This can lead the census to be less than completely accurate. However, the U.S. Census Bureau believes that the latest census — in 2010 — was the most accurate census to date.

So how many people are there in the United States? The U.S. Census Bureau projects that, as of January 1, 2012, the total U.S. population is 312,780,963. Given the information and statistical models used by the U.S. Census Bureau, it is expected that the total U.S. population will increase by one person every 17 seconds in 2012.

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Try It Out

Are you ready to learn more about the census? Don't forget to explore the following activities with a friend or family member:

Head online to check out the Let's Count activity. You'll count items in your home or classroom, record that information in a data table, and then analyze how such data can be used.

If you want to learn more about the state you live in, go to the Census Bureau's State Facts for Students page. Just select your state from the menu and discover all sorts of interesting facts, such as population, largest cities, and even how many fast food restaurants there are!

If you want to keep an eye on how many people there currently are in the U.S. or in the world, check out the Census Bureau's online U.S. & World Population Clocks. Try refreshing the webpage every minute or so to see how much the population estimates increase.

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Wonderopolis

Wonderopolis

Wonder Friend

Mar 15, 2012

How is a census taken? Also when is it taken? Do they take it every few years, every year, or a few times a year? When I say how is it taken, I mean does each family say how many people are in their family or do they just keep record on how many children are born each month, year, or week. I would like to really know the answers to my question because this is a class assignment that we are supposed to do! Go to Wonderopolis!

Wonderopolis

Mar 15, 2012

We're proud of you for doing so much WONDERing about the census, Wonder Friend! We encourage you to re-explore this Wonder of the Day® and click on the links found inside it to learn the answers to your questions! Thanks so much for visiting Wonderopolis! :-)

Wonderopolis

Food Allergy Girl

Mar 3, 2012

Hi Wonderopolis!
I can't believe I am the first one to comment. I think tomorrow's wonder of the day will be about gumballs. This wonder was something I was wondering. That is very neat that the amount of people will increase by one every 17 seconds!
-Food Allergy Girl

Wonderopolis

Mar 3, 2012

Thanks for being the first Wonder Friend to leave us a comment on today's Wonder, Food Allergy Girl! We like your guess for tomorrow's Wonder...we can't wait to visit Wonderopolis tomorrow to see if your guess is correct! :-)